For those of you running IMCA and Nascar Modifieds with an HEI-equipped Small Block Chevy, here's your air cleaner. The 1-1/2'' forward offset is designed to allow HEI distributor clearance. The drop-base model works with 2-barrel Holley carburetors only and features a 1-3/4'' drop for a stacking height of 2-3/4'' above the carburetor neck. The raised base unit fits most all 2 and 4-barrel Holley carburetors and features a 3/8'' raised bottom for a stacking height of 4-3/4" above the carburetor lid. Clear powder coated finish. Comes complete with base, air filter, lid, stud, and wingnut.